A system that navigates to a destination using positioning information is commonly used. The navigation technique in related art sets a destination by using information manually input by a user, preset schedule information, or the like. However, considering the current situation, in some cases, the original destination is no longer an optimal destination at that time. In one example, Patent Literature 1 discloses a technique for informing the opposite party of a schedule change, user's situation, or the like via electronic mail in a short time with a simple operation.